Assuming this is the same claims made on other sites, this abstract clarifies things some (?).The claim of ~ 2000 fold greater energy density applies to a very thin battery (1 micrometer thick). It mentions that this exceeds the best super capacitors in this application and it is generally accepted that super capacitors (excluding EEstor claims) are far behind current batteries for energy density in common applications. I'm guessing it is hard to make good batteries that are only ~ 1 micron thick and this improvement reflects that. So for applications in microelectronics where tiny batteries are needed this may be very useful. But, in everyday battery technology it may be trivial or actually unimpressive . Super capacitors in gross applications (like powering a flashlight) are behind batteries in energy density by several orders of magnitude, so I'm assuming this super thin battery technology is also way behind as the abstract seems to suggest that this super thin battery outperforms similar sized capacitors by a modest (?) amount. Again in microelectronics this may have advantages, but for powering a car or flashlight, it is non applicable. Another case of the media, even supposedly scientifically oriented media getting things way out of perspective.